Epoxy-based nanocomposites for electrical energy storage. I: Effects of montmorillonite and barium titanate nanofillers

Abstract

Quantum dynamics of ultrafast charge transfer at an oligothiophene-fullerene heterojunction J. Chem. Phys. 137, 22A540 (2012) Electrostatic correlations in inhomogeneous charged fluids beyond loop expansion J. Chem. Phys. 137, 104902 (2012) Interfacial electronic properties of the heterojunctions C60/rubrene/Au and rubrene/C60/Au J. Appl. Phys. 112, 023711 (2012) Band offset measurements of the GaN/dielectric interfaces J. Appl. Phys. 112, 024508 (2012) Laterally confined two-dimensional electron gases in self-patterned LaAlO3/SrTiO3 interfaces Appl.Polymer nanocomposites prepared by epoxy reinforced with high permittivity barium titanate ͑BT͒ fillers or high aspect ratio montmorillonite ͑MMT͒ fillers exhibited marked changes in their high electric field properties and their relaxation dynamics, depending on the nanoparticle type and concentration, the nanoparticle size, and the epoxy matrix conversion. We investigated epoxy resin composites based on organically modified montmorillonite ͑oMMT͒ or BT ͑BaTiO 3 ͒ nanoparticles in order to delineate the effects of the high aspect ratio of the MMT and the high permittivity of the BT particles. We also explored the potential benefits of the synergy between the two fillers in systems consisting of epoxy and both oMMT and BT particles. It was observed that the nature of the organic-inorganic interfaces dominate the glass transition temperature and the dielectric properties of these composites. Specifically, using dielectric relaxation spectroscopy, we probed the local dynamics of the polymer at the interfaces. The MMT systems had approximately three orders of magnitude slower interfacial dynamics than those at the BT interfaces, indicating more robust interfaces in the MMT composites than in the BT-based composites; the corresponding energy barriers ͑activation energies͒ associated with these motions were also doubled for the MMT systems. Furthermore, we investigated the effect of the decreased glass transition, interfacial area, polymer-phase at the organic-inorganic interface, and of the dielectric breakdown on the electrical energy storage capabilities of these composites.

Dielectric properties of PZT–epoxy composite thick films

“…A similar trend of reducing the activation energy with increasing the filler factor was reported for ZnO-EPR composites, for which values between about 1.08 eV for 10% ZnO and 0.90 for 70% were determined [33] and for BaTiO 3 /montmorillonite-EPR composites [36]. All these results demonstrate a significant reduction in the energy barriers assigned to the interfacial relaxation (MWS mechanism) which present weaker interactions between the ferroelectric filler and the epoxy network.…”

Barium ferrite/epoxy resin nanocomposite system: Fabrication, dielectric, magnetic and hydration studies

“…Dielectric and magnetic response can be tuned by controlling the amount and the type of the employed ceramic inclusions [14][15][16][17]. Epoxy resins are extensively used for the production of high tech composites in the fields of automotive, aerospace and electronic industries, mostly due to their high stiffness and good adhesion with the inclusions [18][19][20][21]. However, a possible drawback in micro or nano epoxy composites' performance could be related to the effect of environmental attack and the resulting degradation.…”

Dielectric response, functionality and energy storage in epoxy nanocomposites: Barium titanate vs exfoliated graphite nanoplatelets

“…Nowadays a lot of research is carried out in developing compact systems with integrated nanocapacitors, which could act as electrical energy storing devices [3,15e17]. The latter could be used in emerging technological applications such as cellular phones, wireless personal digital assistants, acoustic emission sensors, stationary power systems and hybrid electric vehicles [3,5,18,19].…”